[CentOS] yum/RPM behaviour: does yum/RPM overwrite a file modified by a user during an update ?

Hi,

On our cluster with CentOS 5.5, I have a little problem with a script
for infiniband (this problem:
http://web.archiveorange.com/archive/v/NUQmuN84gd3D31Fdl8PU). So the fix
a very easy. But what will yum/RPM do during the next update ? Will it
overwrite the file ? Will it write on display that the file was modified
by an user (as under debian) ?

Thx a lot,
Best regards,
Guillaume